Modification of Proteins from Soymilk Residue (Okara) by Trypsin

Okara protein isolates were hydrolyzed by trypsin to about 5% to 14%. Solubility was increased more than twofold by the modification, and water hydration capacity and emulsification activity index were also improved. The okara protein products had good essential amino acid profiles and the trypsin‐hydrolysates also had increased in vitro digestibility and available lysine content. The low solubility of okara protein makes it difficult to incorporate it into many food systems. Okara protein hydrolysates, with improved solubility and other functional properties, could be used as a low‐cost protein ingredient in processed foods.